Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751940AbaBBQeB (ORCPT ); Sun, 2 Feb 2014 11:34:01 -0500 Received: from relay.parallels.com ([195.214.232.42]:46397 "EHLO relay.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751686AbaBBQd7 (ORCPT ); Sun, 2 Feb 2014 11:33:59 -0500 From: Vladimir Davydov To: CC: , , , , , , , Subject: [PATCH 3/8] memcg, slab: never try to merge memcg caches Date: Sun, 2 Feb 2014 20:33:48 +0400 Message-ID: <27c4e7d7fb6b788b66995d2523225ef2dcbc6431.1391356789.git.vdavydov@parallels.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.24.25.195] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Suppose we are creating memcg cache A that could be merged with cache B of the same memcg. Since any memcg cache has the same parameters as its parent cache, parent caches PA and PB of memcg caches A and B must be mergeable too. That means PA was merged with PB on creation or vice versa, i.e. PA = PB. From that it follows that A = B, and we couldn't even try to create cache B, because it already exists - a contradiction. So let's remove unused code responsible for merging memcg caches. Signed-off-by: Vladimir Davydov --- mm/slab.h | 21 ++++----------------- mm/slab_common.c | 8 +++++--- mm/slub.c | 19 +++++++++---------- 3 files changed, 18 insertions(+), 30 deletions(-) diff --git a/mm/slab.h b/mm/slab.h index 8184a7cde272..3045316b7c9d 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -55,12 +55,12 @@ extern void create_boot_cache(struct kmem_cache *, const char *name, struct mem_cgroup; #ifdef CONFIG_SLUB struct kmem_cache * -__kmem_cache_alias(struct mem_cgroup *memcg, const char *name, size_t size, - size_t align, unsigned long flags, void (*ctor)(void *)); +__kmem_cache_alias(const char *name, size_t size, size_t align, + unsigned long flags, void (*ctor)(void *)); #else static inline struct kmem_cache * -__kmem_cache_alias(struct mem_cgroup *memcg, const char *name, size_t size, - size_t align, unsigned long flags, void (*ctor)(void *)) +__kmem_cache_alias(const char *name, size_t size, size_t align, + unsigned long flags, void (*ctor)(void *)) { return NULL; } #endif @@ -119,13 +119,6 @@ static inline bool is_root_cache(struct kmem_cache *s) return !s->memcg_params || s->memcg_params->is_root_cache; } -static inline bool cache_match_memcg(struct kmem_cache *cachep, - struct mem_cgroup *memcg) -{ - return (is_root_cache(cachep) && !memcg) || - (cachep->memcg_params->memcg == memcg); -} - static inline void memcg_bind_pages(struct kmem_cache *s, int order) { if (!is_root_cache(s)) @@ -204,12 +197,6 @@ static inline bool is_root_cache(struct kmem_cache *s) return true; } -static inline bool cache_match_memcg(struct kmem_cache *cachep, - struct mem_cgroup *memcg) -{ - return true; -} - static inline void memcg_bind_pages(struct kmem_cache *s, int order) { } diff --git a/mm/slab_common.c b/mm/slab_common.c index 152d9b118b7a..a75834bb966d 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -200,9 +200,11 @@ kmem_cache_create_memcg(struct mem_cgroup *memcg, const char *name, size_t size, */ flags &= CACHE_CREATE_MASK; - s = __kmem_cache_alias(memcg, name, size, align, flags, ctor); - if (s) - goto out_unlock; + if (!memcg) { + s = __kmem_cache_alias(name, size, align, flags, ctor); + if (s) + goto out_unlock; + } err = -ENOMEM; s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); diff --git a/mm/slub.c b/mm/slub.c index 2b1a6970e46f..962abfdfde06 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3686,9 +3686,8 @@ static int slab_unmergeable(struct kmem_cache *s) return 0; } -static struct kmem_cache *find_mergeable(struct mem_cgroup *memcg, size_t size, - size_t align, unsigned long flags, const char *name, - void (*ctor)(void *)) +static struct kmem_cache *find_mergeable(size_t size, size_t align, + unsigned long flags, const char *name, void (*ctor)(void *)) { struct kmem_cache *s; @@ -3707,11 +3706,14 @@ static struct kmem_cache *find_mergeable(struct mem_cgroup *memcg, size_t size, if (slab_unmergeable(s)) continue; + if (!is_root_cache(s)) + continue; + if (size > s->size) continue; if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME)) - continue; + continue; /* * Check if alignment is compatible. * Courtesy of Adrian Drzewiecki @@ -3722,21 +3724,18 @@ static struct kmem_cache *find_mergeable(struct mem_cgroup *memcg, size_t size, if (s->size - size >= sizeof(void *)) continue; - if (!cache_match_memcg(s, memcg)) - continue; - return s; } return NULL; } struct kmem_cache * -__kmem_cache_alias(struct mem_cgroup *memcg, const char *name, size_t size, - size_t align, unsigned long flags, void (*ctor)(void *)) +__kmem_cache_alias(const char *name, size_t size, size_t align, + unsigned long flags, void (*ctor)(void *)) { struct kmem_cache *s; - s = find_mergeable(memcg, size, align, flags, name, ctor); + s = find_mergeable(size, align, flags, name, ctor); if (s) { s->refcount++; /* -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/